In a globalised world, influenced by social flux brought about by various factors¹, cities’ perimeters are subject to continuous change. More often than not, a city’s perimeter expands in the form of urban sprawl. Energy drains from the centre, leaving in its wake numerous vacant, degraded and underutilised structures. Radical interventions on an urban scale are often proposed to counter this degradation and transformation of such urban areas. These interventions² entail densification of the urban fabric, the insertion of additional structures and the creation of new precincts; a process which occurs over many years. By comparison, well-considered alterations to existing built fabric can be implemented quickly with smaller financial and ecological implications. Such alterations also include the adaptation of interior space to support a change in programme, and the possible improvement of a buildings interface with the street. The aim is to improve local social environments within the urban fabric and stimulate social influx. INTERFACE is about interventions to existing structures within the CBD of Pretoria. These interventions are limited to low-rise buildings (between two and five stories) designed specifically for mono-function. Over time, the programme and user profile of those buildings has changed, while the built fabric stagnated, with no active response to its context. Currently, such buildings do not participate in the creation of a living city – a city where interior spaces are supplemented by well designed outdoor spaces, thereby creating places that support and encourage social interaction. Buildings which have simply been taken over and used ad hoc, have not truly been adapted to their new programmes and as such, full exploitation of the space is not possible. Interior spaces can therefore play a determining role in the social motion³ of the city, but only if they address the transition between interior and exterior space, and the extension of such transition into the subsequent urban fabric. These interior and exterior spaces should be adaptable to current social needs of city dwellers and users in order to be deemed successful. Living cities require buildings to adapt and change in response to ever shifting social conditions in order to satisfy basic human desires and needs. It can thus be deduced that a building programme will more than likely change regularly. INTERFACE therefore focus on the creation of responsive interior space and works from the premise that structure and interior are implicitly linked. This thesis explores ‘permanent’ changes to existing structures; changes that will assist in creating responsive interior environments. Such environments should also accommodate both semi-permanent and temporary alterations, with minimal impact⁴ resulting from the implementation of each new programme. 1 Factors: Include change in political, social and economical circumstances. 2 Interventions: In Pretoria CBD, large interventions are proposed over long periods of time. They include strategies such as the Tshwane City Strategy (twenty year),Tshwane Inner City Development and Regeneration Strategy 2005 (ten year program) and City of Tshwane Integrated Development Plan 2009/2010 (five year). 3 Social motion: Interaction and attraction of civilians in a space 4 Impact: Refer to alterations to the permanent responsive structure as well as financial and ecological implications. / Dissertation (MInt(Prof))--University of Pretoria, 2010. / Architecture / unrestricted